1) The document discusses the importance of bounded contexts in software design, particularly for microservices. It notes that bounded contexts allow separating a domain into sub-domains or contexts that each have their own model.
2) The document uses the example of how Amazon might model a book for different purposes like catalog, shipping, etc. It argues that having separate models per context avoids duplication and allows independent evolution of the sub-domains.
3) It provides some heuristics for identifying bounded contexts, such as by sub-domain, common changes, mental consensus of stakeholders, and clustering of functions and data. The document emphasizes that bounded contexts promote loose coupling and independence between contexts.
32. “At Amazon, what a book is for you?”
•Catalog: Picture, title, authors, rating, format
(ebook or paper), category
•Recommandation: List of books often bought
together with it
•Shipping: Dimensions, weight, international
restrictions due to content
•Shopping cart: Price, discount eligible
•Customer review: List of (rating, review,
review rating)
•Book Search: title, isbn, authors
•Search Inside!: full-text content, copyright-
dealing policy
33. One Book. Many Views.
Book To Read
Buyable
Catalog
Shopping Cart
Searchable
Search
Billable
Billing
Recommendable
Recommandation
Priceable
Pricing
Shippable
Shipping
34. “At Amazon, what a book is for you?”
•Catalog: Picture, title, authors, rating, format
(ebook or paper), category
•Recommandation: List of books often bought
together with it
•Shipping: Dimensions, weight, international
restrictions due to content
•Shopping cart: Price, discount eligible
•Customer review: List of (rating, review,
review rating)
•Book Search: title, isbn, authors
•Search Inside!: full-text content, copyright-
dealing policy
1 context
1 model
99. Different Bounded Context
Different MODELs of the same thing
•Catalog: RECORD (Picture, title, authors, rating, format
(ebook or paper), category)
•Recommandation: CLUSTER (List of ID’s often bought
together with this ID)
HEURISTICS
Book:
101. Sub-Domains Names
• Often end in ”-ing” or ”-tion”
• Because purpose verbs made
into nouns
HEURISTICS
102. Mental Consensus of
Everyone Involved
• Directors by departments
(Marketing, Sales, Operations,
Customer Support…)
• Interviews people and listen to
their purpose & language
PRACTICE